Electrical glow-lamp



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H. OOTTRBLL. ELEOTRIUAL GLOW LAMP.

Patentd Feb. 27, 1894.

Nth-515,465.

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Patented Feb. 27, 1894.

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H". COTTRELL.

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No. 515 ,4651 Patented Feb. 27, 1894.

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f UNITED STATES PATENT OFFICE.

HERBERT OOTTRELL, OF NEWARK, NEW JERSEY.

ELECTRICAL G LOW-LAM P.

SPECIFICATION forming part of Letters Patent N 0. 515,465. dated February 2'7, 1894.

l Application filed March so, 1893. I Serial No. 468.30% (No model) To aZZ whom it may concern:

Be it known that I, Hnnennrflorrnmn a citizen of the United States, residing at Newark, Essex county, New Jersey, have invented coating with an electric conductor in a cir-- cuit adapted to induce an electromagnetic discharge across the interior of the bulb. By coating the exterior or interior of the bulb with a conductive substance, I furnish asurface analogous to that used in an electriccondenser, from which the electro-magnetic emanations mayfiow. In some forms of the invention I furnish the'bulb with two conductive bodies connected by wires with the positive and negative poles of an open electric alternate circuit, (as for instanceabattery and induction coil) from the terminals of which the electromagnetic discharge passes through the bulb. In other cases I furnish the bulb with only a single conductive body or coating applied to one side of the same and connected with a single pole, and secure a discharge from such coating through the bulb, by affording a free discharge path to the earth, or its equivalent. In such construction the surface of the g1ass,-opposit'e to that upon which the single conductive coating is applied, forms a true condenser surface, and

- and the body upon the exterior of the bulb is termed the coating, and is preferably connected with the negative conductor; as I find that the light generated by the lamp is more bulb upon its exterior the remainder of the bulbis exposed to permit the difiusion of light when generated. When connected with a suitable generator an intense electro-magnetic discharge is produced between the coating and the central body, and such portions of the bulb as do not lie between these points are also caused to glow with light of considerable intensity. Such glow is caused by the electro-magnetic lines of force which extend in all directions from the coating and the central body, and which produce such glow within the exhausted portion of the bulb. By forming the exterior coating of a reflecting substance like that upon a glass mirror, the light generated in the bulb is powerfully reflected from its opposite side.

In my invention no are or closed circuit is formed between the ends of the wire condoctors, as is common in the use of dynamic electricity in currents of any kind for illuminating purposes, but the glow of the lamp is produced by the electromagnetic lines which intersect the exhausted bulb.

In the drawings, Figure 1 represents in longitudinal section a lamp connected with a lamp socket and having a spherical electrode in the center of the bulb. Fig. 2 is a similar view partly in section, of a lamp with strips of conductive material upon its opposite sides and no electrode within the bulb. Figs. 3, 4, and 5 are perspective views of lamps similar to Fig. 1 with electrodes of different shapes.

Figs. 6 and 7 are a front and edge view of a lamp of modified construction for, medicalexplorations. Figs. 8 and 9 are diagrams of one wire-lamp in section.

The bulb a is shown provided with a tubular neck I) having a metallic collar 0 fixed upon the same to secure the bulb in a lamp holder. The conductive coating d upon the exterior of the lamp is shown in contact with such collar, and the interior electrode eis provided with a conducting wire f extended outside of the lamp through the neck b. To pre vent an electro-maguetic discharge between such wire and the collar which encircles the neck, the wire is coated with glass and may the magneticdischargethan the'vacu-um within the bulb. Such body of air is furnished by means of a glass tube g which is extended through the neck to the center of the bulb and hermetically sealed to :the neck at l'l/Sf outer end. The inner endof the tube is hermetically sealed about the conductor 1 close to the electrode 6 which is thus held firmly in its required position. A plug of plaster or other convenient material 71. is applied to the outer end of the air'tubefgtosustain'the conducting wiref, upon the endof which the coni tact is made in the lamp holder.

The lamp socket 'i is adapted to receive the collar 0 and 'to connect the same by springsj c 'wi'thone pole of the open electric circuit;1 and aseparate conductor-j within the socket audits conductor f. When connected inthe' open electric circuit the discharge between the coating a-nd fthe electrode fills the upper end of the bulb with light, and produces also a strong glow in the lower end of the bulb which is unprovided with a conductive coating.

Dotted lines is of varying intensity are shown extended from the electrode to the coating to illustrate the diffusion of light within the same. 7

It will be observed that the positive and negative conductors which are furnished by the'la'mp socket i are not united in any man- The electrode shown in the center of the lamp and thus illustrated in Figs. 3 to '5 inclusive, may be formed of graphite, carbon, or other conductive material, and I have found-that the admixture of metallic powder or salts with the body of such electrode varies the color of the light produced within the bulb.

With the lamp shown in Fig. 2, two strips or bands (1' of conductive coating, as for instance tin foil, are extended lengthwise of the bulb upon its opposite sides, and connected with the positive and negative poles of the generator. With such construction no inter na'l 'electrodeor conductor is required, but

the electric-magnetic discharge passes across the exhausted bulb from one coating to the other,-and illuminates the bulb in the desired manner. With this construction one of the coatings may 'be insulated -from the interior of the collar 0 by a suitable packing c, and may be extended over the neck I) to make contact with the central conductor j of the socket;- the other strip being connected with the collar and making contact with the exterior of the'socketfas in Fig. 1.

Fig. 3 -represen;ts;a lamp analogous to Fig. 1, with the electrode 6 of conical.form with its apex attached to the conductor f. Two filaments g are shown attached 'to'the' tu-be 9 upon its opposite "sides, and'the'irilo'o'se ends pressed elastically upoii'the base ef the cone. Such filaments may be made of filamentous carbon, and maybe attached tothfe glass tube g by silicate of potassa. To avoid-confusing the drawings, I have'shewn but two of such filaments; butin practice Ihavea -pnea-rmm twelve to twenty of such filaments to the tube,

and find that they greatly enhance the brilliancy of the light, as the filaments radiate light within the bulb in harmony with the electro magnetic discharges. p The coni'c'al electrode, when used ,witliout the filaments, induces brilliant rays-from'the base of the cone, and the whole lamp glows with greater intensity than with a spherical or oval electrode. I p

In Fig. 4 the electrode 6? is shown of egg shape with'small wires or e ndneting eints projected therefrom. With such an electrodethe magnetic discharge is concentrated chiefly upon such points, andthe ill'umiria tion is less intense and less didused than'with a smooth electrode.

In Fig. 5 the bulb is shown with acohductive strip (1 extended from the collar around one side and end of the bulb and partly around the opposite side; while the conducting wire f is projected but very slightly through the neck of the bulb withinthesanie. WVith this construction a flame like that of a candle is manifest upon the electrode f, and a discharge between the same and all parts of the strip 61 fills the interior of the bulb with light.

In Figs. 6 and 7, the bulb is shown of flattened oval form adapted to insert in a patients throat. The electrode 6 is come spon'dingly shaped, like a flat button, and the coating (l -is formed in a circular patch upon one of the flattened sides of the bulb concentric with the edges of the button, and connected with the collar 0 by a strip of the conductive material. W'ith this construction the discharge occurs principally between the electrode e and the disk d but fillsthe remainder of the bulb with its glow, and the disk serves as a reflector to throw the light outward from the opposite side of the bulb. By confining the conductive coating in a zone to one side izo of the bulb, it is enabled to reflect the light outward from the opposite side; but it is obviously immaterial to the production of the discharge upon what part of the bulb the conductive coating is applied. Such coating may be applied to the whole of the lamp if of translucent nature, as thelight would then escape in a considerable degree, or the lamp maybe wholly coated and openings traced or cut in the same to produce apertures of ornamental design through which the light would escape. Such apertures l are indicated in Fig. 4:.

I am aware that an exhausted bulb without any coating has been subjected to the electro-magnetic discharge and its interior caused to glow by such means; but such a bulb is not adapted for commercial use, as it is unprovided with any conductive coating, by means of which the discharge may be localized. By coating the bulb with a conductive substancel amv enabled to direct the electromagnetic discharge through the bulb in any desired manner to produce the greatest degree of light with a given expenditure of energy.

It is obvious that many forms can be given to this lamp to adapt it to various uses, and that various pbosphorescing materials and various vapors and gases can be introduced in the bulb before finally exhausting the same without departing from my invention.

The lamps illustrated in Figs. 1 to 7 inclusive have been first described because they present the most suitable construction for practical use, as the electro-magnetic discharge takes place more readily between two condenser surfaces having an interposed vacuum and no air space; but the bulb may be formed with only a single conductive body or coating, and the discharge may be secured by placing the bulb in proximity toasurface or body of difierent potential. Thus, it the conductive bodyjupon the bulb be connected with the positive pole of an electro-magnetic generator, the discharge may be induced by placing the lamp in proximity to any other object which is in electrical connection with I around its neck, and having an electrical connection with a collarc which is provided with a positive conductor f. A section of a walll is shown adjacent to each of these lamps to representsymbolically anyconducting object of suitable potential near which the lamp may be placed. The presence of such an object, when the conductive body upon the lamp is charged with high potential, induces an electro-magnetic discharge or emanation from such body, which, by the rarefication within of iron in proximity to a magnet concentrates the magnetic lines in great degree upon or through such iron, and in like manner the exhausted space within the bulb concentrates the magnetic lines within the bulb when the discharge is produced. The coating (1 is marked and the wall in Fig. 8 to illustrate the difference of potential between such bodies; but it is obvious that an opposite difference would produce the same eifect, and the conductive body 611 is therefore marked and the wall in Fig. 9 marked From the above description it will be seen that the bulb may be provided with the conductive body or coating in a great variety of forms, and is adapted to glow with the electro magnetic discharge by connection with a single wire, as the conductive body upon the lamp furnishes one surface of an electrical condenser which'isadapted to operate like any other electrical condenser when brought into suitable proximity to a body of different potential. two conductive bodies or coatings which are charged respectively with high and low potential, the construction embodies all the elements for operating in the most perfect manner; but it is well known that a plain glass surface operates as a condenser surface, so that the inner and outer sides of a glass vessel may be in opposite electrical states, and may therefore operate as condenser surfaces independently of any metallic or conductive coatin In the case of an exhausted glass bulb, the presence of the air upon the exterior of the glass operates as a coating, while the comparative absence of air upon the opposite exhausted side operates to sustain an electrical condition diiferent from that of the exterior. This being true, an exhausted bulb with a coating upon the exterior, and having When the lamp is provided witha single electrical conductor only in contact with such coating, possesses two distinct condenser surfaces, one of which is furnished by such exterior coating, and the other of which is furnished by the inner surface of the glass exposed to the vacuum within the bulb. Similar opposite conditions exist with an innor coating exposed to the vacuum and an outer glass surface exposed to the air.

In all of the constructions illustrated, a condenser surface is exposed to the vacuum; the electrodes e, e, c and e furnishing such a condenser surface within the vacuum, and the naked surface of the glass which is exposed to the vacuum furnishing a true condenser surface where no inner coating or electrode is employed.

The essential feature in my invention consists in the subjection, to the action of a varying electro-magnetic orelectro-static field, of one condenser surface exposed to the vacuum of an exhausted receptacle, and another condenser surface exterior to such receptacle and exposed to the air.

My present invention differs from any in which a current is required to pass across the exhausted space, as the latter class of lamps can only be operated with a partial vacuum; while the absolute vacuum is the best medium for the action of the magnetic lines of force and produces an increased efficiency of operation in my construction.

The construction of the electromagnetic generator and the system of connecting and grouping theselamps are the subjects of other inventions and are not therefore described herein. Such lamps may however be connected either in series or in parallel arc, but operate more effectively when connected in parallel are.

What I claim herein is 1. An exhausted bulb having a single conductor only, and a single conductive coating in electrical connection with such conductor through the source of current, as set forth.

2. An exhausted bulb formed with a neck, and provided with a conductive coating upon a portion of the bulbous surface,a contact supporting collar fitted to the neck and electrically connected with such coating, and an electrical conductor connected with such collar, as set forth.

3. An electric lamp, consisting; of an exhausted bulb having a conductive coating upon its exterior, an electric conductor extended from the interior to the outside of the bulb, and a second electric conductor connected with the conductive coating, as herein set forth.

4. An electric lamp, consisting of an exhausted bulb having a conductive coating upon its exterior, a conductor extended from the interior to the outside of the bulb, and a lamp support having positive and negative conductors connected respectively with the exterior and the interior of the bulb, as and for the purpose set forth.

5. An electric lamp, consisting of an exhausted glass bulb, an electrode sustainedwithin the same with a conductor leading outside of the same, a conductive coating applied to the exterior of the bulb, and two conductors connected respectively with the electrode and the coating, as herein set forth.

6. An electric lamp, consisting of an exside of the same, a conductive coatingapplied to the exterior of the bulb upon a portion substantially concentric with the electrode, and a conductor leading therefrom as herein set forth.

8. An electric lamp, consisting of an exhausted glass bulb having a conductive coating upon its exterior, an electrode supported within the bulb, and a conductor extended from the electrode outside of the bulb and surrounded by an annular body of air, and a conductor leading therefrom as herein set forth.

9. An electric lamp, consisting of an exhausted glass bulb, an electrode supported within the bulb, and a conductor extended from the electrode outside of the bulb, and surrounded by an annular body of air, and a conductive coating in a zone upon the exterior of the bulb concentric with such conductor, as set forth.

10. An electric lamp, consisting of an exhausted glass bulb having a tubular neck encircled by a metallic collar,a conductivecoating in a zone about such neck in contact with such collar, and an electrode sustained within the bulb with a conductor extended through the tubular neck, as set forth.

11. An electric lamp, consisting ofan exhausted glass bulb having a tubular neck, a

glass tube fitted in the center of such neck and hermetically sealed to its outer end, a conductor extended through such glass tube and hermetically sealed to the same at its inner end within the bulb, an electrode upon the inner end of such conductor, and a conductive coating applied to the exterior of the bulb, as set forth.

12. An electric lamp, consisting of an exhausted glass bulb having a tubular neck, a glass tube containing air fitted in the center of such neck and hermetically sealed to its outer end, a conductor extended through the air in such glass tube and hermetically sealed to the tube within the bulb, an electrode upon the inner end of such conductor, and a conductive coating applied to the exterior of the bulb, as set forth.

13. An electric lamp, consisting of an exhausted glass bulb, an electrode sustained within the same by a conductor having a coating of insulating material, fibers of conducting material supported upon the coating of the conductor in contact with the electrode, and a conductive coating applied to the exterior of the bulb, as herein set forth.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

HERBERT COTTRELL.

\Vitnesses:

L. LEE, THOMAS S. CRANE. 

